<template>
  <!-- 底部部分 => list有数据的时候，才展示  list.length > 0 -->
  <footer  v-if="list.length" class="footer">
    <span class="todo-count"><strong>{{leftCounts}}</strong>剩余</span>
    <ul class="filters">
      <li>
        <a @click="filter('all')"  :class="{selected: type ==='all'}"  href="#/">全部</a>
      </li>
      <li>
        <a @click="filter('active')" :class="{selected:type ==='active'}"  href="#/active">进行中</a>
      </li>
      <li>
        <a @click="filter('completed')" :class="  {selected:type ==='completed'}" href="#/completed">已完成</a>
      </li>
    </ul>
    <!-- 有已完成的任务，才需要显示这个按钮 -->
    <button  v-if="isShowClear" @click="clear" class="clear-completed">清除已完成</button>
  </footer>
</template>

<script>
export default {
  props:{
    list:{
      typeof:Array,
      require: true
    }
  },
  data(){
return{
  type:'all'
}
  },
  computed:{
    leftCounts(){
      return this.list.filter(item=>item.flag===false).length;
    },
    isShowClear(){
      return this.list.filter(item=>item.flag===true).length>0
    }
  },
  methods:{
    clear(){
      this.$emit('clear');
    },
    filter(){

    }
  }
}
</script>

<style></style>
